Conventional "on-edge" mail stacking devices are usually composed of a transport followed by various forms of stacking mechanisms. Generally, multi-bin on-edge stacking devices include gating mechanisms which divert specific mailpieces, i.e. envelopes, into predetermined stacker bins. The lead edge of the mailpieces are urged against a fixed registration surface in the bin. Such on-edge stacking devices are well known. The overwhelming majority of these devices stack mailpieces received in a vertical orientation on a horizontal surface.
Typically, in an on-edge stacking device envelopes are transported vertically along a dual belt transport system, deflected into a stacker bin by a deflector mechanism, and guided into the bin by conventional guide and urging components. The envelopes always stop against some sort of vertical registration surface. Since on-edge stackers currently used in mail sorting applications typically process a variety of envelope sizes concurrently, this vertical registration surface must be located in a compromise position to satisfy the requirement of both small envelopes (6" long) as well as large envelopes (12" long).
If conventional on-edge stackers are interfaced to the output of inserters, the stacking reliability suffers because such stackers are structured to handle a variety of envelope sizes. However, inserters process one size envelope at a time, rather than the concurrent processing of envelopes ranging from 6" to 12" in length. As a result, the reliability of on-edge stacking of envelopes output by an inserter suffers.
It is an object of the present invention to provide a simple stacking device which yields highly reliable stacking of any size envelope output from an inserter.